Problem: Everything that isn't made by a AAA game studio is called an indie game nowadays.
Solution: I will no longer call my games indie games, they are doujinsoft now.
This actually got me wondering, is calling what you do doujin only admissible if you’re from Japan
I would argue it is extremely OK to do so no matter where you're from.
as someone who plays doujin games a lot, roughly speaking, doujin media is simply self-published media you and your buds made. a lot of game jam titles on itch would qualify as doujin stuff for example.
i recently had to translate an interview with ZUN (touhou guy) who distinguished “consumer” games (commercial titles that appear on consoles, smartphones, and steam) from his average touhou games. since fangames are appearing on these more commercial platforms with his blessings, the distinction is necessary and touhou can’t simply be regarded as “PC games” — there is a huge difference between offering them on steam and buying them from brick and mortar stores that specialize in doujin media.
of course, we live in the age of the internet and this isn’t applicable to most of us outside japan. so a good way to understand whether something is doujin media or not is through mass-scaled distribution and marketing. these days, many doujin games can appear on steam through publishers like henteko doujin and kagura games. but obviously, they are no annapurna since they serve as translation spaces and don’t have some epic marketing department.
doujin vs indie is a real debate in japanese spaces as well, but i find it kinda pointless to think about quality. it’s not about price — there are many free vns with high quality production but they are made by corporations for example — nor is it about the storyteling scale (astlibra is a long free jrpg that now appears on steam as a paid remake). doujin media can certainly be profitable if one looks at the state of dlsite rpg maker games and asmr, which blurs the distinction between doujin and indie. so a meaningful way to distinguish is marketing reach and distribution.
tldr: if a game you like has like no marketing outside a bunch of people who say it’s good on twitter, probably doujin because doujin media has no giant publishing arm. they’re just average blokes like us.